Bitcoin payment processor BitPay has signed more than 2,500 merchants as clients in the past three months, which brings the number of merchants in Europe using the service to more than 11,000.

Those merchants processed more than 28 million euros this year in bitcoin payments compared to 1.4 million euros for the same months in 2013—a growth of 1900%. BitPay says the countries in Europe with the highest adoption rates are the United Kingdom, Germany and the Netherlands. BitPay plans to open a larger office in Amsterdam to keep up with the growth. Worldwide, BitPay has 75 full-time employees and five offices in Atlanta, Amsterdam, San Francisco, Buenos Aires and St. Petersburg.

“In May when we first opened the office, we were adding about 200 merchants monthly, and for the month of August we added 1,100 new merchants in Europe,” says Moe Levin, director of European business development for BitPay. “Europeans are familiar with multiple currencies and are at the forefront of mobile technology adoption, so it’s easy to see why bitcoin is popular and widely used.”

Bitcoin is a decentralized—meaning no one organization regulates it—digital currency that buyers and sellers exchange over the Internet, with no bank involvement. The value of all the bitcoins on the market at the end of the first quarter of 2014 was estimated at $6.45 billion, according to CoinMarketCap.com, which tracks the valuations of virtual currencies across major exchanges. That value changes as new bitcoins enter into circulation and as the currency’s value itself fluctuates.

Large U.S. e-retailers such as Overstock.com Inc., No. 31 in the Internet Retailer Top 500 Guide, Dell Inc., No 10; Newegg, No. 17; and 1-800-Flowers, No. 65.